The board of Best Buy Co. is investigating allegations that CEO Corrie Barry had an inappropriate romantic relationship with a fellow executive who has since left the retailer.

According to various media reports, the action came after the board received an anonymous letter signed “We are Best Buy” that claimed to represent “a group of employees.” The letter, dated Dec. 7, was also sent to several news organizations, including the Star Tribune. The letter writers said Barry should resign or the board should fire her.

Best Buy has hired an outside counsel, Sidley Austin LLP, to conduct an investigation “that is ongoing,” it said in a statement.

“Best Buy takes allegations of misconduct very seriously,” the company’s statement said. “We encourage the letter’s author to come forward and be part of that confidential process.”

In a statement, Barry said: “The Board has my full cooperation and support as it undertakes this review, and I look forward to its resolution in the near term.”

Barry, formerly Best Buy’s chief finance and strategic transformation officer, took the reins as CEO in June 2019, succeeding Hubert Joly, who transitioned to the newly created position of executive chairman. She is the first woman ever to serve in the top role at Best Buy and one of just seven women to lead a Fortune 500 company.

According to the Star Tribune, the letter said that Barry had a romantic relationship for years with Karl Sanft, whose final position at Best Buy was as a senior VP who oversaw retail store operations in the U.S. He left Best Buy in March and is now the COO of 24 Hour Fitness Worldwide Inc.